Evaluation of Porous, Geotextile Liners for Erosion Control in Small Aquaculture Ponds

摘要

Two geotextile liners, one with 0.090-mm openings and the other with 0.355-mm openings, were each installed in three 0.04-ha earthen ponds at the E. W. Shell Fisheries Center, Auburn, Alabama. Geotextile liners did not tear or decay during the 2-year study, and they prevented erosion of pond bottoms compared with three unlined ponds. However, the liners with 0.090-mm openings floated up into the water column in all three ponds, while the other liner floated up in one pond. Production, survival, and feed conversion ratio for hybrid catfish (female Channel Catfish Ictalurus punctatus x male Blue Catfish I. furcatus) did not differ (P > 0.05) among control and lined ponds. Phytoplankton abundance as estimated by chlorophyll a concentration was greater in lined ponds-especially in those lined with the less permeable geotextile-than in control ponds. This difference was attributed to differences in phosphorus uptake by bottom soil among lined and control ponds. Control ponds had higher turbidity than lined ponds in spite of greater chlorophyll a concentration in the lined ponds. This was the result of sediment resuspension by aeration in the unlined ponds. In laboratory tests, geotextiles with openings of 0.090-0.840 mm did not allow normal exchange of phosphorus between soil and water. Nevertheless, if the floating problem could be solved, porous geotextiles should be given further consideration for erosion control in small ponds and possibly in intensive, heterotrophic floc systems for commercial culture of marine shrimp and a few other species. They probably are too expensive for use in large ponds for green-water culture of fish and shrimp.